Various technologies of switching the power supply voltage supplied to an amplifier circuit have been proposed (for example, see Patent Document 1). In the power amplifier circuit of this Patent Document 1, a low voltage is normally supplied as the power supply voltage, the power supply voltage is switched to a high voltage when a large signal is input, and the occurrence of frequent switching is prevented by providing hysteresis for the switching between the high voltage and the low voltage and by making switching to the high voltage only when the number of times the signal input level exceeds a threshold value becomes equal to or greater than a predetermined number of times.